Hello, with the increased activity on 50MHz WSPR in the last 2 months, the ability to monitor stable signals over many paths has become available to us all. As I am working around the place putting up a plaster board ceiling in the shack (a long and dusty story), I have been taking rest breaks to look at what's going on with WSPR and rest my arms and have a drink.

One thing that has come of my observations is the sheer number of meteor ping and burns that can be seen in the WSPR display during the day. While these events do not add any value to those using WSPR (some might say its annoying as it corrupts WSPR decodes) it is interesting to see how often they occur in what is often thought to be a low time for meteor activity.

While this may be no surprise to others, I did think it worthy of posting and seeing what others had to say about their experiences with day time meteors.

Meteors do indeed enter the atmosphere at all hours of the day and night. There is a peak in the return rates (pings and burns) just before dawn and a corresponding dip 12 hours later. This is more to do with the entry velocity of the rocks (actually most are grain of sand size) than the actual number of meteors.

There is an optimum size and velocity for meteors to create the ionized trails which refract and scatter the signals back to earth. Below a certain velocity they do not burn up at the height of the E layer (100 km) and do not produce the required ionisation

On the dawn/morning side of the globe the surface of the earth is "turning into" the interplanetary dust clouds ahead of the planets orbit and so the velocity of the earths surface, as it rotates, is ADDED to the velocity of the meteors. The meteors appear to be moving faster

On the dusk/afternoon side, the earth rotation is turning away from the earths orbit so the surface velocity is SUBTRACTED from the velocity of the meteors making them appear to move slower.

Its the same analogy as bugs hitting the windscreen of a car. You don't find to many stuck to the back window